Cambridge University Library have now put the Darwin manuscripts and publications on line. This facility has made his work available to everyone for the first time. The works include the draft of his theory of evolution from 1842 and notes from his voyage on the Beagle 1831-1836. I have just downloaded his 1871 book - The Descent of Man (first edition) - in its two volumes. This will be the first time that I have read this early work. I read his 1882 The Descent of Man (second edition) some years ago.
Link to Darwin on line
I am in favour of making such works available for everyone to read. In the past I have transcribed and translated papers on fossil pterosaurs to make them available on line. Lets have lots more of this type of work on the internet.